Luminous signs employing a gaseous discharge and the methods for making these signs have been disclosed in several patents. In general, these signs are made by using two or three glass plates where in one or two of the plates is formed a groove or cavity corresponding to the desired display. The cavity is hermetically sealed and attached to a gas entry port incorporating a set of electrodes. In the manufacturing process the cavity is evacuated and a quantity of gas, such as neon, is introduced into the cavity through the gas entry port. The gas is then ionized by applying a voltage across the electrode set. The ionized gas, in turn, causes the display to illuminate.
Although the many known variations on luminous signs have been proven to perform satisfactorily, further improvements on luminous signs and methods of manufacture are desired.
Accordingly, it is an object of the invention to provide a highly reliable luminous gas discharge display capable of being manufactured of most any suitable material which can withstand normal operating temperatures and vacuum levels of gas discharge illumination displays. Further, it is an object of this invention to provide a means of isolating the gas discharge display itself from the high temperatures involved in forming of electrodes of the display.
A further object of the invention is to provide a gas discharge display which maintains the optical clarity and transparency of the glass plates from which it is manufactured.
Another object of the invention is to provide that the evacuation and gas filling means to be accomplished through the same holes and tubes used to house the electrodes.
In addition, it is an object of this invention to provide that the sealing of evacuation, gas filling and electrode preparations be done to the back panel only, not to both the front and back panels.
A further object of the invention is to provide a luminous gas discharge display using low temperature sealing glass or high vacuum epoxy alone to provide a hermetic seal for the display.
Yet another object of the present invention is to provide a luminous gas discharge display that is simple and economical to manufacture.